Boiler construction.



D. D. SHERK.

4BiLEF CONSTRUCTION.

APPLICATION man Mn Patented A111220, 1915.

saires oraison BEARELL D. SHIERK, RGCKFORQQLLNOXS, ASSGNOR 0F NE-THIRD TG WILLIAM 5. STE'WARD, 0F ROCKFORR LLINQISfL :seinen coiisrnnorroii.

' T0 all whom t may concern and useful improvements in Boiler Construction, of which the following is a speci fica-tion. f A

rllhis invention relates in general to steam boilers-and more particularly to locomotive boilers and more specifically has reference structed the walls o'ijvthe fire box, the top of which is commonly referred to as the crown sheetfand the sidesas the side sheets, are sei, curely connected to. the surrounding boiler shell by stays and braces designed to preclude deformation of the sheets-under pressure. The stays, commonly known as stay bolts, are customarily4 threaded through alined tappedv holes in the boiler shell and re box sheets, the inner ends of the bolts being thenv riveted over against the inner -face ror the sheets. l The expansion and contraction of the sheets from exposure `to the high tempera ture in the fire box and the stra-ins to which the sheets and tbe stay bolts are subjected by the high boiler' pressure and as the result of vibration of the engine and the shocks and jars incident to the ruiming oi" the locomotive cause the metal of the sheets around the holes through which the stay bolts pass 'to Icrystalline and diminish in strength, the stay bolts have a tendency to work loose in the sheets, 'thereby resulting in leakage around the bolts from the boiler into the lire box. And if the bolts are 'tightened up by further riveting their inner ends, as is customarily done, the blovvs of the riveting operation tend still further to crystallize the sheets so that sooner or later the sheets will, fracture and crack around the stay bolt holes, thus'4 necessitating a renewal of thesheet at very great expense.

One of the primary objects of my present invention is to obviate the objections above. mentioned which are inherent in boilers as ordinarily built, by providing a boiler construction embodying imperforate crown-and side sheets so that these sheets Will not be weakened by stay bolt holes but .will possess and retain their original strength.

Another object of my invention is to securely attach the stay bolts to the imperferate crown and side sheets Without insertion through' the sheets, this object being attained by securing the stay bolts to the outer l faces only of the sheets in a novel manner, to the construction of and the connections` to be later mores-fully explained.

Another object of the invention is to. rigidly connect the stay bolts vboth with the boiler shell and the lire box sheets Without y riveting the bolts, thereby eliminating not only the riveting operation itself but also obviating the weakening and crystallizing of the metal Which inevitably results from the blows of the riveting hammer.

A furtherobject of the invention-is to -increase the efficiency of the boiler'by increasing the radiating surfaces of the side and crown sheets, the radiating surfacesof which are materially decreased in the ordinary boiler constructon by the heads of the stay bolts on the inside of the fire box.

Still another object is to providea boilel,`

construction in which the stay bolts can be quickly and easily removed and replaced for purposes of repair entirely from outside the tages of my invention will be readily appreciated by those skilled in the art as the invention is more fully understood by reference to the following description-When con sidered in connection with the accompanying drawings.

boiler and by .one man, thus effecting a Referring to the drawing'siligure 1 is a I fragmentary cross sectional view of a loco-V motive boiler embodying my invention Fig. 2 is an enlarged vieri7 showing the details of my improved construction, andf'g. B isa view taken on the line-3413 of Fig. 2.

By reference to Fig. 1 of the drawings it will be observed that reference character 5 vindicates the shell of a boiler surrounding the lire box 6, the walls of which, comprising the crown sheet 7 and the side sheets 8,-will be hereafter referred to as the fire box sheets. In this as in other boiler constructions the lire box sheets and the boiler shell are connected together and reinforced at frequent intervals by stay bolts arranged substantially as shown in Fig.. l.

InsteadA of making holes in the fire box sheets and extending the stay bolts through them and riveting over the inner ends of the bolts as has' heretofore been done, with the consequent weakening of the sheets as has been previously explained, I make provision for attaching the inner ends of the stay bolts to the outer faces only of the sheets by punching out from the body of the metal of which the sheets are composed, a plurality of hollow nipples 9 as shown in Fig. 2. One of these nipples is formed for each stay bolt and after the nipples have been punched out they are threaded exteriorly as indicated by reference character 11.

The boiler shell 5 is provided with tapped openings 12 corresponding in number and location with the nipples 9, the openings being of sufficient size to permit the insertion therethrough of the enlarged hollow heads 13 of the stay bolts 14. The stay bolt heads 13, which are preferably circular in cross section, are hollowed out or cupped, as shown in'Fig. 2, and interiorly threaded as indicated by reference character y15 to lit the threads -11 on the nipples 9 so that the bolts may be ixedly and rigidly but yet detachi ably secured to the re box sheets by threadirg them onto the outwardly projecting nipes 9. p The outer ends of the stay bolts 14 are threaded as indicated by 16 and a rigid connection is established between the stay bolts and the boiler shell by means of rings or bushings 17, tapped to fit the stay bolt thread 16, and exteriorly threaded tobe screwed into the boiler shell holes 12. The outer ends of the bushing 17 are squared as indicated at 18 to receive a wrench, by means of which the bushings are screwed into position. The stay bolts are preferably formed with a central bore 19 to provide the required telltale hole through which escaping steam or water Igvilll call attention to a broken or cracked o t.

In assembling my improved construction after the lire box sheet has been positioned and riveted in Yplace by the usual rivets around its periphery the stay bolts are inerted through the shell holes 12 from the outside and threaded ontol the nipples 9.

-Any suitable tool of well known construction may be employed for screwing the bolts tightly onto the nipples. The bushings 17 are then threaded onto the outer ends of the.

bolts and into'the tapped openings 12 to thereby rigidly connect the stay bolts with the shell. It will thus be manifest that the stay bolts can be quickly and easily connected up by one man outside the boiler.

be quickly and easily removed by unthreading the bushing 17 and unscrewing the bolt from its nipple.

So far as I am aware I am the first to p rovide a locomotive boiler construction embodying imperforate crown and side sheets so that the sheets possess and retain full and original strength of the metal. It is to be understood that the crown and side sheets are, strictly speaking, not imperforate for the reason that they are provided with the usual riveting holes around their peripheries for the accommodation of fastening rivets, but the sheets are imperforate except for these marginal riveting holes, and as distinguished from the sheets heretofore used the word imperforate `correctly describes my novel sheets.

' It should be manifest that the imperforate sheets shown and described possess much greater strength than the old style sheets having holes through which thel stay bolts extend; that -the radiating surface of Vthe sheets is materially increased over the radiating surface of the old style sheets which were reduced in radiating eliiciency by the ends of the stay bolts projecting therethrough, and that in my present construction original construction and because of the saving in time and labor required in making repairs when such become necessary. Obviously the details of construction illustrated and described are capable of considerable modification and variation without departing from the essence of this invention, as set'forth in the appended claims.

I claim:

1. A boiler construction compi-'sing an imperforate fire boxsheet, and m ans attached to the outer face of said sh t at intervals throughout its area for holding said sheet against deformation.

2. A boiler construction comprising an imperforate fire box sheet provided on its 1,1eega74 p outer face with a plurality of integral nipples, and means attached to said nipples for holding said sheets against deformation.

3. A boiler construction including an imperforate lire box sheet provided on its outer face with a plurality of eXteriorly threaded nipples.

4. A boiler construction comprising an imperorate fire boxsheet provided on its outer surface with threaded nipples, and stay bolts having their inner ends in threaded engagement with said nipples.

5. A boiler construction comprising an imperforate fire box sheet, a .boiler shell, and means attached to the outer face of said sheet Without passing Ithrough the sheet and connected with said shell whereby said sheet is held against distortion.

6. A boiler construction comprising a, tire box sheet provided on its outer surface with a plurality of nipples a boiler shell provided with openings arranged in alinement with said nipples, stay bolts connected at their ends of said stay bolts and with the Walls of said shell openings.

8. A boiler construction comprising a fire box sheet provided on its outer surface with a threaded nipple, a stay bolt having an enlarged tapped inner end threadedly engaged With said nipple, a boiler shell, and a bushing rigidly connected with said shell and with said bolt.

' DEARELL D. SHIERK.

lVitne'sses:

JOHN F. MCCANNA, DELLA ATKINsoN.

bushings threadedly engaged With the outer 

